don't link the flowparser unless actually requested

Summary: Don't try to link the Flow parser unless it is enabled.

Reviewed By: avp

Differential Revision: D19804094

fbshipit-source-id: 9ef147db499e58aa844e943b0b80c507083543b8

CMakeLists.txt

@@ -413,13 +413,15 @@ else()
   set(CORE_FOUNDATION "")
 endif()
 
-if (CMAKE_SYSTEM_NAME STREQUAL Darwin AND NOT HERMES_BUILD_32_BITS)
-  set(LIBFLOWPARSER ${CMAKE_CURRENT_SOURCE_DIR}/external/flowparser/libflowparser-mac.a)
-elseif (CMAKE_SYSTEM_NAME STREQUAL Linux AND NOT HERMES_BUILD_32_BITS)
-  set(LIBFLOWPARSER ${CMAKE_CURRENT_SOURCE_DIR}/external/flowparser/libflowparser-linux.a)
-else()
-  set(LIBFLOWPARSER "")
-  set(HERMES_USE_FLOWPARSER OFF)
+if (HERMES_USE_FLOWPARSER)
+  if (CMAKE_SYSTEM_NAME STREQUAL Darwin AND NOT HERMES_BUILD_32_BITS)
+    set(LIBFLOWPARSER ${CMAKE_CURRENT_SOURCE_DIR}/external/flowparser/libflowparser-mac.a)
+  elseif (CMAKE_SYSTEM_NAME STREQUAL Linux AND NOT HERMES_BUILD_32_BITS)
+    set(LIBFLOWPARSER ${CMAKE_CURRENT_SOURCE_DIR}/external/flowparser/libflowparser-linux.a)
+  else()
+    set(LIBFLOWPARSER "")
+    set(HERMES_USE_FLOWPARSER OFF)
+  endif()
 endif()
 
 if (HERMES_USE_FLOWPARSER)